Background

Research has shown that reducing SUDs through effective treatment leads to a reduction in criminal activity\(^{[1]}\). However, most evidence comes from developed countries, and results from the Latin American context are largely unknown\(^{[2]}\). The social, cultural, economic, epidemiological context and substance use treatment (SUT) policy response are different in this region, making the question about SUT effectiveness through locally based data relevant\(^{[3]}\). We analyzed Chile as a case study and examined the impact of SUT on the prevention of contact with the criminal justice system (CJS) in the middle (3 years) and long term (5 years).

Methods

• Design: a population-based record-linkage retrospective cohort design.
• Participants: patients enrolled in publicly funded SUT programs in Chile, 2010-2019.
• Exposure: Treatment completion, Late (>= 3months of treatment) & Early dropout (<3 months); Outcome: contact with the CJS (offenses ending with a condemnatory sentence and offenses that ended with imprisonment after baseline treatment outcome)

Analysis plan

We calculated cumulative incidence rates and incidence rate ratios(IRR)

We used Royston-Parmar survival models and adjust for the effects of other factors, and predicted standardized survival probabilities and restricted mean survival times (RMST)\(^{[4]}\).

We imputed missing data under MAR assumption\(^{[5]}\).

We calculated e-values of the strength of confounding needed to take away the associations between treatment outcome and contact with CJS

Codes are available at https://fondecytacc.github.io/nDP/index_prop_grant22_23.html. Covariates are listed below:

Treatment setting

Sex

Substance use onset age

Educational attainment

Primary substance at admission

Primary substance at admission usage frequency

Occupational status

Poly-substance use

Number of children (binary)

Tenure status of households

Macrozone

Number of previous offenses (violent)

Number of previous offenses (acquisitive)

Number of previous offenses (substance-related)

Number of previous offenses (other)

Psychiatric comorbidity (ICD-10)

Substance use severity (dependence status) (ICD-10)

Urban/rural municipality of residence

Percentage of poverty of the municipality of residence

Initial substance

Birth year

Cohabitation status

Physical comorbidity

Admission Age

Preliminary Results

Of the 109,756(patients= 85,048) SENDA records of admissions, 70,863(83%) were eligible to be matched with the Prossecutor’s Office database (discarded ongoing treatments or treatments that ended in referrals).

Condemnatory sentence. 22,287(31%).

Imprisonment. 5,144(7%).

• Early dropout vs. Treatment completion: Patients completing treatment took longer to an offense leading to condemnatory sentence (IRR= 2.18 95% CI 2.09,2.27; aHR[adjusted hazard ratio]: 1.74 95%CI 1.66, 1.83) condemnatory sentence and imprisonment (IRR= 2.90 95% CI 2.64,3.18; aHR= 1.99 95%CI 1.79, 2.22).
• Late dropout vs. Treatment completion: Patients completing treatment took longer to condemnatory sentence (IRR= 1.73 95% CI 1.67,1.80; aHR=1.58 95%CI 1.52, 1.65) and to imprisonment (IRR= 1.93 95% CI 1.77,2.10; aHR=1.65 95%CI 1.51, 1.81).
• Late vs. Early dropout: Patients completing treatment took longer to condemnatory sentence (IRR= 1.26 95% CI 1.22,1.30) and imprisonment (IRR= 1.50 95% CI 1.41,1.61).

E-values

Condemnatory Sentence: E-value of at least 2.19 for Early and 2.01 for Late dropout vs. treatment completion at baseline (t=0).

Imprisonment: E-value of at least 2.99 for Early and 2.38 for Late dropout vs. treatment completion at baseline (t=0).

The following figure depicts the predicted differences in survival probabilities and RMTLs for committing an offense that results in a condemnatory sentence and imprisonment.

Discussion

• SUT can be effective in preventing contact with the criminal justice system (CJS) in Chile.
• More research is needed to understand the effects of SUT on contact with the CJS.
• Completing SUT can help to reduce the harms of substance use disorders and criminality.

References

Funding sources